Tacoma’s board of ethics declined to ding Mayor Marilyn Strickland over her appearance in a promotional video released by the company that wanted to build a methanol production facility at the Port of Tacoma.

The volunteer board late Monday dismissed a complaint filed by resident Claudia Riedener, who alleged Strickland in the video revealed a bias in favor of a methanol proposal that was the subject of a city-led environmental review.

Board Chairman Joseph Atkinson disclosed little about how he and his colleagues reached their decision, except to say Strickland’s appearance in the video did not transgress the city’s code of ethics.

The city “code of ethics is very specific of what we can find a violation to be,” he said.

Northwest Innovation Works last month canceled its proposal to build the world’s largest methanol plant at the port. The company had planned to produce methanol here and ship it to plastics manufacturers in China.

Strickland filmed a supportive message in September in which she touted the project’s potential to bring jobs to the city, as well as to reduce global greenhouse gas emissions by limiting China’s need for coal-fired energy.

The company released the video in March, after the city had taken control of the project’s environmental review.

Its release followed remarks Strickland made at a February City Council meeting when she urged colleagues to refrain from taking public stands on the controversial proposal so they could maintain an appearance of neutrality while city staff members carried out the environmental study.

Strickland in March called her decision to participate in the video “an error” that contradicted her previous message to the City Council.

Riedener and about 10 members of the anti-methanol group Red Line Tacoma attended the ethics meeting.

They were asked to leave while the four-person board of ethics considered the complaint in a closed portion of its meeting. That part of the meeting was closed so the commission could hear confidential legal advice from a deputy city attorney.

Riedener and other methanol critics were frustrated by the decision and how the discussion took place in private. They referred to the board as a “club” when they left the meeting. A couple of them cursed the commission in a small meeting room.

“How can she be in a commercial supporting Northwest Innovation Works and still remain neutral?” Riedener said.

Riedener cannot appeal the board’s decision.

She acknowledged the complaint was moot because the project has been canceled, but she said she worried that other public officials have been unethically endorsing another proposal that would allow Puget Sound Energy to build a liquid natural gas peak shaving plant at the port.

That project has broad support from labor and many political leaders. Red Line Tacoma and the Puyallup Tribe have been charging that it is unsafe.